text: One modification of a reaction developed by this scientist reacts an allylic ether or thioether with a ketene to form an unsaturated ester or thioester.
full_question: One modification of a reaction developed by this scientist reacts an allylic ether or thioether with a ketene to form an unsaturated ester or thioester. Another modification of the same reaction developed by this man forms gamma, delta-unsaturated carboxylic acids from the rearrangement of deprotonated allylic acetates, and is named for Ireland and this scientist. This man also names a reaction used in the first step in the mevalonate pathway, which forms the molecule acetoacetyl-CoA. Unsaturated ketones are formed from allyl vinyl ethers in this man's rearrangement, a variant of the Cope rearrangement. Dieckmann names an intramolecular version of this man's most famous reaction. For 10 points, name this German chemist whose namesake condensation of two esters forms beta-keto-esters.
first_sentence: One modification of a reaction developed by this scientist reacts an allylic ether or thioether with a ketene to form an unsaturated ester or thioester.
raw_answer: Rainer Ludwig Claisen