POLYLITHIUMORGANIC COMPOUNDS .12. REDUCTIVE SCISSION OF A CYCLOPROPANE SIGMA-BOND DURING THE ACTION OF ELEMENTAL LITHIUM ON CYCLOPROPYLACETYLENES - A CIS-1,2-DILITHIOALKENE AS INTERMEDIATE

The cis‐dilithioalkene 2 a is stable in solution at −30 °C; it is formed as intermediate during the reductive cleavage of a cyclopropane bond in 1 a leading to 3 a. In contrast, in the analogous reaction of 1 b, only the product 3b of ring‐opening can be detected, and no intermediate. R = Ph(a), cyclopropyl (b). (Figure Presented.) Copyright © 1990 by VCH Verlagsgesellschaft mbH, Germany