Lecture 4 - Cycloadditions - Diels Alder Stereochemistry OH S 8 products Dieneophile comes Dieneophile comes Different approaches of dieneophile from the Bottom from the Top OH S "exo approach" OH "exo approach" OH f. f OH + f. } "endo approach" "endo approach"

HN03 A, rC=N H2504 HN03 b, H2S04 Give the products Jor the above reas. Do each f these reoctions go faeter or slower than Berzene a s a star ting ma terial ?

Praw the product obtainal: CH2 -CH3 | product Prene Dienophile Please show all arrow puslhing meehamsms for Diels-Alden renstim. Thank you! ↑

Which of the following would be the most reactive in a Diels-Alder [4+2] cycloaddition as the diene? 0000 2 = = - IV || ||| IV

H ОНС H H CH3 H CHO H CH3 CN NC H H H a b d Rank these dienophiles in decreasing order of reactivity in the Diels-Alder reaction. Most reactive = 1, least reactive =4.

C. SN1 SN2 E1 E2 Initial Stereochemistry R CH3 H3C-CH2- -CH OH R TSCI (with pyridine) and -OCH2CH3 + Product(s)/Stereochemistry(ies) of reaction c

Draw the starting diene and dieneophile

Anser correctly , the previous answer wad wrong and i downvoted that so answer all parts correctly

Arrange the following groups in the order of decreasing priority (highest priority to lowest priority). - CH=CH; -C=CH –CEN -C=0 CH; I II IV O> II> III> IV Oll> IV> I> I| OIV> III> II> I Ol> I> IV> I| %3D

e. cis-2-butene + Br2 H3C-CH=CH-CH3 Major Product(s) of e. Stereochemistry of the product described in e. (Circle one) а. R b. S С. Е d. Z e. a mixture of E and Z f. erythro g. threo h. a racemic (50/50) mixture i, all 4 products (a set of ervthro and a set of threo) i. no stereochemistry