Dihalocarbenes have been generated by thermal decomposition
of sodium trichloroacetate and tribromomethylphenylmercury, and
give mono dihalocyclopropyl adducts with steroid dienes. Such
compounds offer an easy starting point for the synthesis of unusual
derivatives of potential biological interest. Under the same conditions,
however, addition to non-conjugated double bonds does not
take...
Thermal decomposition of several di-p-toluenesulfonylhydrazones
was studied. It was found that the carbene decomposition
of tetramethyl-1,3-cyclobutanedione, di-p-toluenesulfonylhydrazone
gave two products resulting from
rearrangement. One was identified as 2,5-dimethyl-1,3,4-hexatriene. A tentative structure for the second was
proposed. During the course of the study, a more convenient
procedure for thermal decompositions was...
Examination of a proposed reaction scheme to prepare bicyclo-(2.2.0)hexan-1-ol produced the first known condensation of an
enamine with its carbonyl precursor. Hydrolysis of the resulting
dienamine gave an unusual conjugated cyclobutenone in which the
double bond is exocyclic. Characterization and reactions of the
cyclobutenone were successfully carried out.
Steroid organoboranes have been found to be useful synthetic
intermediates. Attempted pyrolyses, based on simple trialkylborane
cyclizations, have not yielded C-19 or C-18 functionalized steroids,
but have produced isomerized systems not otherwise available.
Thus, hydroboration of cholesterol followed by pyrolysis at
215° gives 31% of 2-cholestene-6α-ol and 49% of a...
The 3-cyclohexenyl carbinyl carbene species was formed by the
thermal decomposition of the p-toluenesulfonylhydrazone sodium
salt and by oxidation of the hydrazone. Several oxidizing agents
were studied. The products were investigated under aprotic and
protic conditions and at various temperatures. The diazocompound
was formed as an intermediate and found to...
A facile route to bicyclo(2.1.1)hexanes was developed involving
the intramolecular photocyclization of 1, 5-hexadien-3-one to
bicyclo(2.1.1)hexan-2-one. A study of the chemistry of bicyclo-(2.1.1)hexan-2-one was undertaken. Deuterium exchange and borohydride
reduction demonstrated the strain present in the ketone.
Further evidence was obtained from the failure to introduce substituents
alpha to the...
Cyclopropylcyclobutene was prepared via the intermediate
dicyclopropylcarbinyl carbene which was generated by the thermal
decomposition of the sodium salt of dicyclopropylketone p-toluenesulfonylhydrazone.
The successive thermal isomerization of cyclopropylcyclobutene
to 2-cyclopropyl-1, 3-butadiene and to vinylcyclopentene
was studied. Kinetic data were obtained for the cyclopropylcyclobutene
to 2-cyclopropyl-1, 3-butadiene isomerization in the gas...
An examination was made of some reactions involving a transfer
of carbon from boron to carbon. In the case of the reaction of
a C[subscript n] alkylorganoborane with dichlorocarbene the intermediate was
a C[subscript n]₊₁ chloroalkylorganoborane. Oxidation of this intermediate
yielded an homologous acid (33%) and the usual alcohol (66%)....
New syntheses for 2-bicyclo(3.3.1)nonanone and 7-bicyclo-(3.3.1)nonen-2-one were developed. The saturated ketone was prepared
from phenol and acrylonitrile via a novel intramolecular
S[subscript N]2 cyclization process. A Friedel-Crafts cyclization of 3-(3-cyclohexenyl)propanoyl chloride permitted synthesis of the unsaturated
ketone from 4-cyclohexene carboxaldehyde. The formation of
the bicyclo(3.3.1)nonane rather than a bicyclo(3.2.2)nonane skeleton...
Dihalocarbenes have been generated mainly by thermal decomposition
of sodium trihaloacetate and phenyl (trihalomethyl)mercury,
and give gem-dihalocyclopropyl adducts with various steroid olefins.
A new procedure involving the use of sealed tubes makes possible the
addition of dihalocarbenes to sterically hindered olefins. In this manner,
7-cholestenyl benzoate when treated with PhHgCC1₃...