論文句子4

Question 1

First, Woodward recognized that by using a differentiated quinone nucleus it would be possible to effect regioselective control of the intermolecular Diels ± Alder union, as the more electron-rich methoxy-substituted olefin would be less dienophilic than its methyl-substituted counterpart.

Answer 1

as: 當…時.連接詞

Question 2

An equally insightful design element was the anticipation that even though a cis-fused adduct would arise from the Diels ± Alder reaction, conversion into the requisite thermodynamically more stable trans-fused system present in the targeted natural products would be relatively simple to achieve.

Answer 2

anticipation:預期
though: though是從屬連接詞後面需逗號，雖然
arise from : 由…引起
requisite: 必要的

Question 3

Thus, in the next synthetic operation, base-induced epimerization readily provided the coveted trans-fused ring system (10), thus setting the stage for an eventual ring-contraction process that would allow completion of this region of the steroid nucleus.

Answer 3

thus跟therefore同樣是副詞，副詞可以放在句首，但是不是連接副詞，所以若要連接句子需加連接詞