What is a good synonym for「〜のに」at the end of a sentence?

Question

I'm trying to come up with a good synonymous expression to put on a flashcard for 「〜のに」at the end of a sentence like these

• 彼が出て行けばいいのに。(I wish he would go.)
• あの建物さえなければ、きれいな景色が見えるのに。(If it wasn't for this building, we could see a beautiful scenery.)
• 欲しいといえば、買ってあげたのに。(If you had told me, I would have bought it for you.)
• ああ、せっかく学校が休みなのになあ。(Ahh, just as school is closed for vacation [I have to study for an entrance exam (or similar)])

I would probably translate 「〜のに」 with wish, should etc.

My dictionary explains that it is used to express dissatisfaction, irritation and similar feelings. I'm wondering what Japanese expressions I should use if I were to rephrase the sentences above without 「のに」. Would any of the following be correct and/or appropriate? What else?

• 〜という希望がある
• 〜べき・はずだ

Answer 1

How about んだけど

彼が出て行けばいいんだけど。
あの建物さえなければ、きれいな景色が見えるはずなんだけど。
欲しいといえば、買ってあげたんだけど。

Maybe no real synonym, but it is also a conjunction with the rest of the sentence omitted. のに means "although" and けど means more "but", but I guess that is close enough.

In your last example せっかく…のに is a set phrase and のに can't be removed so easily.

I'm also wondering about your translation, which obviously has more detail than the original sentence. Even taking this into account, the translation of なのに sounds strange. I imagine the sentence ending in something like

ああ、せっかく学校が休みなのに、剣道部でめちゃくちゃ忙しくなりそうだ。
Just as there is no school, it looks like I'm going to be really busy with Kendo.