Boranes needle, double-ended

Ethereal methyllithium from methyl chloride added slowly under N2 with Dry Ice-acetone cooling via the double-ended needle technique (s. H. C. Brown et al., Organic syntheses via boranes, Wiley, 1975, p. 210) to a mixture of B-ethyl-9-borabicyclo[3.3.1]nonane and dry pentane, stirred 10 min. at -78°, allowed to come to room temp., stirred 1.5 hrs., water-cooled, acetyl chloride added drop-wise from a syringe, and stirred ca. 2 hrs. -> c/>y-bicyclo[3.3.0]oct-l-ylethylmethyl-borane (Y 97%) treated with alkaline HgOg in tetrahydrofuran cw-bicyclo-[3.3.0]octan-l-ol (Y 95%). - The above rearrangement by a variety of reducible compds. (in the above case acetyl chloride, which is converted into ethyl acetate) furnishes many compds. containing the d5 -bicyclo[3.3.0]oct-l-yl moiety whidi have previously been difficult to prepare. F. e. s. G. W. Kramer and H. C. Brown, Am. Soc. 98, 1964 (1976) one-pot procedure s. J. Org. Chem. 42, 2832 (1977). 

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