Spiro Centre Research Articles

Conformational effects in spiro-fused azirines

Analysis of the n.m.r. spectra of azirines (5)–(8) together with the X-ray crystal structure of (7) reveals that a requirement for near-coplanarity of three bonds at the spiro centre results in conformational anchoring of the five-membered ring.

Circular dichroism of diastereomeric 3,3′-di-t-butyl-1,1′-spirobi-indans

Two diastereomeric 3,3′-di-t-butyl-1,1′-spirobi-indans, (1R,3S,3′S)-(1a) and (1S,3S,3′S)-(1b), have been prepared; their c.d. spectra are similar to each other in spite of the opposite configuration at the spiro centre.