.D D2 Pd-C н н B.

Synthesize (Z)-hept-5-en-2-one from ethyl acetoacetate (CH3COCH2CO2Et) and the given starting material. You may also use any other organic compounds or required inorganic reagents.

(a) Draw the mechanism for the formation of both of the enols that can be formed from A (use acetic acid & AcOH as the source of the protons) (b) Draw the mechanism of reaction of this enol with bromine to give product B

Ribose, a carbohydrate with the formula shown, forms a cyclic hemiacetal, which, in principle, could contain either a four-membered, five-membered, or six-membered ring. When D-ribose is treated with methanol in the presence of an acid catalyst, two cyclic acetals, A and B, are formed, both with molecular formula C,H,0, These are separated, and each is treated with sodium periodate (Section 10.8C) followed by dilute aqueous acid. Both A and B yield the same three products in the same ratios. он о CHO СНО H+ CH,OH A +B ÕH 1. NalO, 2. H,0* НО CHO + CHOH + CH,OH ÕH CH,OH Isomeric cyclic acetals with molecular formula CH12O, D-Ribose (C;H1605) From this information, deduce whether the cyclic hemiacetal formed by D-ribose is four- membered, five-membered, or six-membered.