The hydronaphthacene ring system consists of five fused six-membered rings, as shown below in compounds 3 and 4. One method forconstruction of this ring system involves treatment of compound 1 with an organometallic reagent such as 2, called a Fischer carbene.(Tetrahedron Lett. 2011, 52, 4182-4185). Two diastereomeric products are obtained, 3 and 4, differing only in the configuration at onechiral center.SiMe,Cr(CO)5OMeMe,SiHO2CHOMe,Si1SiMe,3 - (R)4 - (S) Select the choice(s) that describes how you could distinguish these two products using only 1³C NMR (select all that apply).O Compound 4 lacks an internal plane of symmetry, so it has a greater number of signals in its 13C NMR spectrum.O Compound 4 has an internal plane of symmetry, so it has fewer signals in its 13C NMR spectrum.O Compound 3 lacks an internal plane of symmetry, so it has a greater number of signals in its 13C NMR spectrum.O Compound 3 has an internal plane of symmetry, so it has fewer signals in its 13C NMR spectrum.

Ans) Compound 4 has an internal plane of symmetry, so it has fewer signals in its 13C NMR spectrum.

The hydronaphthacene ring system consists of five fused six-membered rings, as shown below in compounds 3 and 4. One method for construction of this ring system involves treatment of compound 1 with an organometallic reagent such as 2, called a Fischer carbene. (Tetrahedron Lett. 2011, 52, 4182-4185). Two diastereomeric products are obtained, 3 and 4, differing only in the configuration at one chiral center. SiMe, Cr(CO)5 OMe Me,Si HO CHO 1 Me,Si SiMeg 3 - (R) 4 - (S)

The hydronaphthacene ring system consists of five fused six-membered rings, as shown below in compounds 3 and 4. One method for construction of this ring system involves treatment of compound 1 with an organometallic reagent such as 2, called a Fischer carbene. (Tetrahedron Lett. 2011, 52, 4182-4185). Two diastereomeric products are obtained, 3 and 4, differing only in the configuration at one chiral center. SiMe, Cr(CO)5 OMe Me,Si HO CHO 1 Me,Si SiMeg 3 - (R) 4 - (S)

Organic Chemistry

8th Edition

ISBN:9781305580350

Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Publisher:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Chapter21: Benzene And The Concept Of Aromaticity

Section: Chapter Questions

Problem 21.55P

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