Reaction of silyl thioketone 7 with lithium diethylphosphite at-98 °C afforded an S-attack product 8 and a formal C-attack products 10 and 11, which were formed by S-to-C migration of the phosphoryl group in 8 followed by C-to-S migration of the silyl group (thia-Brook rearrangemnet), in a ratio depending on the conditions. The relative facility of the thia-Brook rearrangement was compared with that of the Brook rearrangement using the (t-butyldimethylsilyl)diphenylmethyl derivatives 22 and 23.

[reaction: see text] A newly developed strategy for eight-membered carbocycles via [3 + 4] annulation that involves the combination of beta-substituted acryloylsilanes and enolates of cycloheptenone is described. A unique feature of this annulative approach is its capacity to generate, in two steps, eight-membered ring systems containing useful functionalities for further synthetic elaboration from readily available three- and four-carbon components.

9‐Bromphenanthren wird durch eine Grignard‐Reaktion in das o‐Tolylderivat (Ia) und weiter mit N‐Bromsuccinimid sowie Anilin über (Ib) in die Titelverbindung (IIa) umgewandelt.

rings with 7 or more members rings with 7 or more members Q 0050 -079Stereoselective Construction of Eight-Membered Carbocycles by Brook Rearrangement-Mediated [3 + 4] Annulation.-An efficient method for the stereocontrolled synthesis of eight-membered carbocyclic compounds bearing various functional groups (V) is presented, involving the Brook rearrangement-mediated [3 + 4] annulation reaction of β-substituted acryloylsilanes (I) with cycloheptenone enolates (II), followed by diastereoselective hydroxylation and oxidative cleavage of the α-hydroxy ketone moiety.