Answer Happy

OH Base tBu D tBu E tBu F tBu G NaBH4 aqueous work up tBu B (1:1 cis/trans mixture) i) Provide conformationally accurate drawings of cis and trans isomers of molecule B. For both the cis and trans isomers, draw a Newman projection of the whole molecule showing the "flattening" of the ketone, indicate bonds that are gauche and antiperiplanar to the chloride. [5%] ii) Reduction of ketone B with sodium borohydride (NaBH4) affords alcohol C as a mixture of stereoisomers. Using conformationally accurate drawings throughout, provide a curly arrow mechanism for the reaction, and discuss any selectivity observed (indicate the type of stereoisomerism products exhibit). (10%) iii) Reaction of the mixture of stereoisomers with a strong base, affords the mixture of compounds D, E, F, G. Using conformationally accurate drawings throughout, provide a curly arrow mechanism accounting for the formation of each product. (10%) iv) Based on the reactivity of sodium borohydride (NaBha) with B, and on your understanding of the reaction of C with a strong base, rank D, E, F, G from major to minor product