An optical active compound A (C12H16O) shows amongst other a strong IR-absorption at 3000 – 3500 cm- — Physical Chemistry — Thermodynamics Chemistry Question
Structure Elucidation of an Optically Active Compound
An optical active compound A (C12H16O) shows amongst other a strong IR-absorption at 3000 – 3500 cm-1, and two medium signals at 1580 and 1500 cm-1. The compound does not react with 2,4-dinitrophenylhydrazine (2,4-D). Upon treatment with I2/NaOH, A is oxidized and gives a positive iodoform reaction.
Ozonolysis of A (1. O3; 2. Zn, H+) gives B (C9H10O) and C (C3H6O2). Both B and C give precipitation when treated with 2,4-D, and only C gives positive reaction with Tollens reagent. Nitration of B (HNO3/H2SO4) may give two mono-nitro compounds D and E, but in practical work only D is formed.
Acidification followed by heating of the product formed by the Tollens reaction on C gives compound F (C6H8O4). The compound gives no absorption in IR above 3100 cm-1.
Based on the above information draw the structure formula(e) for the compounds A – F and give the overall reaction scheme, including the (2,4-D) and the products of the Tollens and iodoform reactions.
Draw C in an R-configuration. Transform this into a Fischer projection formula and state whether it is a D or L configuration.
Model Answer
R-configuration D-configuration