Enamine intermediates carbocyclization

Oxazine JV-oxides 386 obtained from cross-conjugated keto enamines 384, and 1-nitrocyclohexene 385 do not ring open to nitroalkylated enamines, but undergo ring fission and rearrangement to five-membered carbocycles - . Nucleophilic ring fission of 386 to the intermediate 387 followed by recyclization gave the hexahydroindene... 

A. Carbocyclic - A few new methods are available to prepare the steroidal skeleton. For tne most part, these involve variations of the previously reported methods for the total synthesis of steroids. Racemic equilenin is prepared stereo-specifically starting with 2-bromo-6-methoxynaphthalene and the i "butyl enol ether of 2-methyl-l,3-cyclopentanedione. Estrone was prepared from the cheap natural product eugenol the key intermediate m-methoxyallylbenzene. Progress toward the total synthesis of terpenes, specifically the pentacyclic triterpene alnusenone, is reported. The synthesis of B-nor, B-nor-D-homo, or normal steroids by the use ot an electrophilic reagent on a bicyclic enamine is recorded. In addition, a bicyclic intermediate can be converted into a D-homo-8g-methyl-B-norestrane. ... 

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