3): a) Metalation of (2) (1 g, 5.9 mol) in pentane (10 ml) with one equivalent of t-BuLi at 0 °C for 12 h furnishes a product, which, after removal of solvent, has the composition corresponding to (3a); dec. pt. 90 "C, soluble in ether, THF, dioxane.-b) Addition of TMEDA and of pentane to an ethereal solution of (34 leads on cooling to quantitative precipitation of the crystalline complex (3); m. p. 70 "C.
(4): Reaction of (3a) with excess benzyl bromide in pentane at 20 "C for 12 h and separation of LiBr affords (4) in 74% yield; m.p. 123 "C (from THF).
(6): Metalation of (5)I5] with excess CH3Li in ether at 0 "C, followed by reaction with excess CHJ and hydrolytic workup, furnishes (6) in 95% yield; m.p. 197 "C (dec., from (7): HBr gas is passed into a solution of (2) (2.61 g, 15.9 mmol) in benzene (100 ml) until evolution of H2 ceases. Yield 75% after removal of benzene and crystallization from CH2C12 at -78°C; m.p. 131 "C.
(9): A solution of (8)[61 (0.9 g, 6 mmol) in THF (10 ml) is allowed to react with one equivalent of H3B. C4Hs0 for 1 h at 20°C. Removal of solvent, dissolution of the residue in benzene, filtration, removal of benzene, and crystallization from pentane affords (9) in 80% yield; m. p. 46 "C. CH2CIZ).